Strong and Multicolor‐Tunable Pure Organic Circularly Polarized Room‐Temperature Phosphorescence from Cholesteric Liquid Crystal

Abstract Pure organic circularly polarized room‐temperature phosphorescence (CPRTP) materials show significant promise for applications in advanced anti‐counterfeiting, biological imaging, and so on. However, it remains challenging to prepare CPRTP materials with a high phosphorescence luminescence dissymmetry factor (g_lum). This article provides a simple and efficient method to prepare pure organic CPRTP materials with high phosphorescence g_lum from cholesteric liquid crystals by incorporation of achiral phosphorescent chromophore dibenzofuran into chiral cholesterol mesogen via a flexible spacer. The findings show that the synthetic compound Chol‐C6‐DF can form cholesteric liquid crystals and can effectively amplify the g_lum value through selective reflection. The Chol‐C6‐DF film can produce yellow CPRTP when excited by a dibenzofuran chromophore. The g_lum value, the lifetime, and the quantum yield of the yellow CPRTP produced by dibenzofuran under the excitation of 380 nm light are −0.19, 567.7 ms, and 3.2%, respectively. Even more interesting is that the chiral cholesterol also exhibits RTP and clustering‐triggered emission characteristics. The g_lum value and the lifetime of red CPRTP produced by cholesterol under the excitation of 420 nm light are ‐0.11 and 1.11 s. Under excitation of 410, 430, and 470 nm light, the phosphorescent quantum yields are 19.0%, 20.2%, and 19.1%, respectively.